Why do dogs eat grass? 

If the above photograph of a dog eating grass looks familiar, you are not alone. With the exception of the proper food to feed your pet, there is perhaps no other question that elicits as many varied responses as this one. So what is the answer? Well, as it turns out, there isn't a single one.

People typically fall into three categories when it comes to answering this age-old question:

the firstthe dog has an upset stomach and is eating grass to make him or herself vomit

the second: because dogs evolved from wild canines, such as wolves, they instinctively eat grass because the animals they consumed in the wild did so. In other words, they are accustomed to eating grass from the bodies of prey.

the third: dogs eat grass because they are lacking something in their diet - something that is satisfied by chomping on the green stuff whenever they are able

We found only one recent study on this question - and the results were inconclusive. In 2008, researchers at the University of California, Davis found the most likely (though not definitive) reason that dogs eat grass was ancestry; that is, there might be a predisposition due to genetics.* There was no evidence that dogs lacked nutrition, nor did a statistically significant number of them vomit after consuming grass.

As always, talk with your veterinarian if you observe any new or unusual behavior in your pet - including eating grass. But if it's something he or she does regularly without incident, chances are he or she simply likes it.

For more information about the UCDavis study, read the article in Psychology Today here.

*Read the full UCDavis study: Sueda, K.L.C.,Hart, B.L. & Kliff, K.D. (2008). Characterization of plant eating in dogs. Applied Animal Behavior Science, 111, 120-132

photo source Creative Commons